The present invention relates generally to vehicle windows and, more particularly, to vehicle windows having electrical elements, such as defroster elements or antenna elements, at a surface of a glass sheet of the window, and a method and apparatus for attaching such electrical elements to the glass sheet.
Many windows for vehicles, such as rear windows or windshields or the like, include electrical components or conductive elements, such as defrosting heater elements, such as defroster lines, strips or coils, or antenna elements or the like at or along a surface of a glass sheet of the window. Such conductive elements typically comprise electrically conductive silver flakes, which are mixed with low melting glass and applied or screened as a thick film to a surface of the glass sheet for the window or to a ceramic frit layer on the surface of the glass sheet. The silver layer is typically applied when the glass sheet has been cut to its desired shape and/or when a ceramic frit layer has been applied or screened to portions of the glass sheet. The glass sheet, which includes the defroster strips and conductive elements, is typically heated in a furnace to heat the glass to its melting point and to melt and fuse the silver conductive flakes and ceramic frit. The heated glass sheet is then molded to its desired shape and quickly cooled or tempered to achieve the tempered glass for the window. Typically, this is performed at a window or glass sheet manufacturing plant or fabrication plant.
Typically, after the glass sheet is formed, a number of such glass sheets are packaged and moved to another area of the glass manufacturing plant to have an electrical connector or clip attached to the silver conductive element. Typically, the connector is soldered to the conductive layer that is on a surface of the glass sheet at the end of the conductive line or strip. This is accomplished by various known soldering approaches, such as induction heating, contact heating or resistance heating, whereby the solder on the clip is heated to melt the solder and then cooled to secure the solder and the clip to the silver layer and frit layer on the glass sheet. Such known methods of soldering the connector to the conductive layer or element typically are capital intensive and may require costly equipment and/or typically provide challenges or difficulties in process control.
After the connector or tab is attached to the conductive element on the surface of the glass sheet, the glass sheet is not as well suited for dense packaging as it was before attachment of the connector. Therefore, the glass sheets are typically repacked in a less dense manner after attachment of the connectors and are then shipped to a vehicular or modular window assembly or manufacturing line, typically at a different assembly plant or facility, for further processing, which may include adding hinges, seals, frames or the like to the glass sheet to complete the modular window assembly. Such a conventional process is shown generally in FIG. 1.
Because of the costs and challenges associated with such known methods of attaching the electrical connectors, and because of the time involved in heating and cooling the connector, solder layer and glass sheet during such attachment processes, such approaches are typically performed at the glass sheet fabrication plant and are not suited for application at the modular window assembly plant. Therefore, the glass sheet of a vehicle window currently is typically packaged two times within the glass sheet fabrication or manufacturing plant, such that the current process is inefficient and, thus, may add to the cost of the completed window assembly. Also, because the electrical connector is typically mounted or secured to the glass sheet at the glass manufacturing plant, the glass sheets may be packaged in a less dense manner when transported to the vehicular or modular window assembly plant, which is typically remote from the glass manufacturing plant.
Therefore, there is a need in the art for a window manufacturing and assembling process that overcomes the shortcomings of the prior art processes.
The present invention is intended to provide an apparatus and method for attaching an electrical connector to a conductive element, such as a silver conductive layer, such as an antenna element or defrosting heating element, of a glass sheet of a vehicular or modular window assembly. The connector may be soldered to the conductive element or bus bar of the glass sheet, which may comprise a tempered glass sheet or other type of glass sheets, such as an annealed glass sheet, a laminated glass sheet or the like, and may comprise a tinted or untinted glass sheet and/or may include solar coatings or the like, by heating the solder joint via substantially infrared radiation heating. The method is preferably performed at a vehicular or modular window assembly line or plant or facility, where a frame and/or hinge and/or other components may be assembled or applied to the glass sheet portion of the modular window assembly.
According to an aspect of the present invention, an electrical connector is applied to a conductive element, which is deposited or disposed on a surface of a glass sheet of a window and exposed at a terminal end of an electrical element, via radiation heating of the connector or a solder layer at the connector with an infrared radiative heating device. The conductive element may be a silver conductive layer or line, such as an antenna element or defroster heater element or the like. The heating device preferably comprises an infrared lamp and a reflector, which functions to focus or channel or funnel or otherwise direct the radiant energy from the lamp selectively to the region of the solder joint to be established, while minimizing radiant heating of peripheral and adjacent regions of the glass sheet or panel. The infrared lamp is operable to generate infrared radiant energy, which preferably is in the short wavelength or far infrared region, such as around 800-1500 nm, more preferably approximately 1000-1300 nm, and most preferably approximately 1100-1200 nm, at a target or focal region generally corresponding with the location of a solder layer or the like between the electrical connector and the conductive element. The connector preferably includes a layer of solder or other suitable material deposited on or integral with the surface of the connector to be connected to the conductive element, such that when the solder and/or connector are heated to a desired temperature, the solder melts and then cools and refreezes to bond or adhere to the conductive element on the glass sheet or window surface.
According to another aspect of the present invention, a method for applying an electrical connector to a conductive element disposed on a surface of a glass sheet of a window comprises providing a glass sheet having a conductive element disposed on a surface thereof. A substantially infrared radiative heating device is provided which comprises an infrared lamp and a reflector configured to focus or funnel or otherwise direct radiant energy from the lamp at a target or focal region. An electrical connector is positioned at the conductive element of the glass sheet, and the heating device is positioned relative to the glass sheet such that the target or focal region corresponds generally with the solder joint or solder layer between the electrical connector and the conductive element of the glass sheet. The electrical connector is attached to the conductive element via radiation heating of the solder layer with the infrared radiative heating device.
The electrical connector may be applied to the conductive element via radiation heating of a layer of solder at a surface of the electrical connector to be connected to the conductive element, such that when the solder and the electrical connector are heated to a desired temperature, the solder melts and then cools and refreezes to bond or adhere to the conductive element on the window surface.
The heating device may comprise a shaped reflector, such as a parabolic-shaped reflector or an ellipsoid-shaped reflector or a nozzle-shaped reflector or the like, which is shaped or configured to direct radiant energy from the lamp at a target or focal region. The shaped reflector may comprise a truncated ellipsoidal reflector defining first and second focal points. The infrared lamp may be positioned generally at the first focal point and the target or focal region may be generally at the second focal point.
The radiative heating device may rapidly and substantially heat the solder layer, while substantially limiting or substantially avoiding directing radiant heating energy to the glass sheet. The heating device may include a shield or holding device which temporarily holds the electrical connector at the glass sheet during the radiation heating process and substantially limits directing of heat toward and to the glass sheet and/or substantially limits dissipation of heat into the glass sheet by shielding the glass sheet from the energy generated by the radiative heating device.
The electrical connector may be positioned at a first surface of the glass sheet, while the heating device is positioned at a second surface of the glass sheet which is opposite the first surface. The heating device may be operable to radiate energy through the glass sheet to the target or focal region at the first surface of the glass sheet. The target region and solder layer at the electrical connector may thus be heated by the heating device, while the glass sheet and surrounding area are not substantially heated.
The glass sheet may be manufactured or fabricated at a glass or window manufacturing or fabrication plant or facility and then may be transported to a vehicular or modular window assembly plant or facility remote from the glass manufacturing plant. The electrical connector may be attached to the conductive element of the glass sheet at the modular window assembly plant.
According to another aspect of the present invention, an attachment system for attaching or soldering an electrical connector to a glass sheet comprises a heating device and a holding device. The heating device comprises an infrared radiative heat source positioned at least partially within a shaped reflector. The shaped reflector is shaped or configured to focus or channel or funnel or otherwise direct infrared radiant energy from the lamp at a target region. The holding device is configured to temporarily hold the electrical connector during the heating process. The heating device and the holding device are arrangable relative to one another and relative to the glass sheet such that the holding device and the electrical connector are positionable generally at a surface of the glass sheet and the heating device is positionable generally at the holding device with a solder layer being generally at the target region. The heating device is operable to generate and direct the energy at the target region to heat and melt the solder layer while the holding device holds the electrical connector and substantially limits directing of the energy to the glass sheet.
The shaped reflector may comprise a parabolic-shaped reflector, an ellipsoid-shaped reflector and a nozzle-shaped reflector. The shaped reflector preferably comprises a polished metallic interior surface for reflecting and directing the energy at the target region.
The holding device generally surrounds the electrical connector and substantially limits directing of the infrared radiant energy to the glass sheet, such as around the electrical connector to the glass sheet, during the heating process. The holding device may comprise a base portion and a pivotable portion which is pivotable relative to the base portion to release the electrical connector as the holding device is moved from the electrical connector and the glass sheet.
Therefore, the radiation heating device and process and system of the present invention provides for rapid heating of a layer of solder at a window element or electrical connector at a glass sheet, while substantially limiting directing of the heat to the glass sheet. Therefore, the soldering process may be completed in a short period of time without substantially heating the glass sheet, such that the attachment of the window element to the glass sheet may be performed at a modular window assembly plant, which typically attaches a frame, seal and/or hinge or the like to the glass sheet. Also, because the radiation heating process of the present invention requires less capital investment than known induction heating processes, the radiation heating process may be performed by the final modular window assembler or manufacturer. The glass sheet window portions thus may be densely packaged a single time by the glass sheet manufacturer or at the glass manufacturing plant or glass fabrication plant (which cuts, shapes and tempers the glass and applies the frit layer and electrical or conductive layers or lines to the glass sheet) and then shipped to the vehicular or modular window assembly plant, which then may add the frame portions, seals, hinges and/or the like and the electrical connectors to the glass sheet portions. The completed vehicular or modular window assemblies are then shipped to the automotive manufacturer""s assembly plant for installation on vehicles. Because the window elements, such as electrical connectors and/or the like, are applied or attached or soldered to the conductive elements on the glass sheets at the modular window assembly plant, the glass sheets may be densely packaged for shipment to the modular window assembly plant, and may be only packed and unpacked one time, thereby providing a lower cost manufacturing process for vehicle modular window assemblies.
These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.